1. Field of the Invention
This invention relates to an outboard motor shift control system.
2. Description of the Related Art
In most outboard motors, shift change is conducted by operating a shift mechanism equipped with a dog clutch, either manually or by use of an actuator, as taught, for example, in Japanese Laid-Open Patent Application No. 2003-231498 (particularly paragraph 0022 and FIG. 4). Specifically, shift change is conducted by sliding a clutch formed with projections, manually or by use of an actuator, so as to bring the projections into engagement with projections provided on a forward gear or projections provided on a reverse gear.
When the shift mechanism is operated by an actuator, it is necessary to detect clutch position for controlling the operation of the actuator. The clutch position has conventionally been detected using a sensor, such as a potentiometer or an encoder, or a switch, as taught, for example, in Japanese Laid-Open Patent Application No. 2000-85688 (particularly paragraph 0039 and FIG. 3).
The position of the clutch when shift change is completed (when the clutch has been slid to the point that the tips (tops or distal ends) of the clutch projections (teeth) or the tips of the gear projections (teeth) strike against recesses (the lands between the projections) of the other of these members) may differ in one and the same shift mechanism owing to aging (projections wear and the like) and between different shift mechanisms owing to manufacturing variances. Completion of shift change can therefore not always be accurately ascertained when a sensor or switch is used to detect clutch position.